perfect now was the co-ordination between infantry and guns, and so masterful the allied artillery, that it is highly probable that at last the defence was losing as many as the attack. Those deep ravines which had enabled the Germans to escape the effects of the early bombardments no longer existed in the new lines, and the superficial ditches which now formed the successive lines of defence offered little protection from a fire directed by a most efficient air service. On the other hand, since the German air service had been beaten out of the sky, the sight of the German gunners was dim, and became entirely blind when by their successive advances the Allies had pushed them over the {104} low ridges which formed their rearward positions. The map, however skilfully used, is a poor substitute for the observation officer and the aeroplane. Standing on the edge of this welter, and gazing at this long haze into which vigorous divisions continually plunge, relieving exhausted units, only to stagger out in their turn, rent and torn, while yet others press to the front, one feels appalled at the difficulty of following such complex operations and of conveying them clearly and in their due order to the mind of the reader. Some fixed system must evidently be followed if the narrative is to remain intelligible and the relation of the various actions to each other to be made evident. Therefore the course of events will still, so far as possible, be traced from the north, and each incident be brought to some sort of natural pause before we pass onwards down the line. We can at once eliminate the whole northern portion of the British line from the Gommecourt salient down to Albert, since for that long stretch attack had changed definitely to defence, and we start our narrative from the south of the Albert-Bapaume road. From that point four villages immediately faced the old British line, and each was now a centre of fighting. From the north they were La Boiselle, Fricourt, Mametz, and Montauban. The latter had been held against a strong counter-attack on the early morning of July 2, and it was firmly in the possession of the Thirtieth Division. Mametz was held by the Seventh Division, who were pushing on to the north, driving a weak resistance before them. Fricourt had been deserted by the morning of July 2, and had been occupied by the Seventeenth Division, who also at once pushed on towards the woodlands {105} behind. La Boiselle was closely assailed with part of the Thirty-fourth Division to the south of it, and the Twelfth and Nineteenth Divisions with other troops all round it. These four villages and the gaps between them represented the break in the German front line.